Added basic implementation of the lgamma, digamma, igamma, igammac, polygamma, and zeta function for fp16
Added basic implementation of the lgamma, digamma, igamma, igammac, polygamma, and zeta function for fp16

ROCmSoftwarePlatform/hipeigen,ritsu1228/eigen,ROCmSoftwarePlatform/hipeigen,ROCmSoftwarePlatform/hipeigen,ritsu1228/eigen,ROCmSoftwarePlatform/hipeigen,pasuka/eigen,pasuka/eigen,pasuka/eigen,ritsu1228/eigen,pasuka/eigen,ritsu1228/eigen,pasuka/eigen,ritsu1228/eigen